The purpose of the present study was to observe the structure and functional change of the bone-coating-prosthesis interface in vivo and to evaluate the histocompatibility of self-made prosthetic femoral components in the body and the degree of their bonding with the surrounding bone tissues as well as their stability. Six mature beagle dogs underwent bilateral hip replacement with prosthetic femur components. Three groups were established in terms of different coating of prothesis (four joints in each group): atmosphere (A) plasma-sprayed pure titanium (Ti) prosthetic joint with hydroxyapatite (HA) coating (HA+Ti+A group); vacuum (V) plasma-sprayed pure Ti prosthetic joint with HA coating (HA+Ti+V group); vacuum plasma-sprayed pure Ti prosthetic joint with Ti-HA stepped coating (Ti+HAG+Ti+V group). The hip joints were functionally evaluated, and subjected to X-ray examination, biomechanics inspection, and histological examination. As a result, X-ray imaging revealed all prosthetic joints were in a good location and no dislocation of joint was found. Shear strength of interface was significantly higher in Ti+HAG+Ti+V group than in HA+Ti+V group (P<0.05) and HA+Ti+A group (P<0.05) at 28th week. Histological examination showed the amount of newborn bone in Ti+HAG+Ti+V group was more than in HA+Ti+V group and HA+Ti+A group after 28 weeks. It was suggested that vacuum plasma-sprayed pure Ti prosthetic joint with TI-HA stepped coating could improve the bonding capacity of bone-prosthesis, enhance the stability of prosthesis, and increase the fixion of prosthetic femoral components because of better bone growth. This new type of biological material in prosthetic femoral components holds promises for application in clinical practice.
Animals ; Biomechanical Phenomena ; drug effects ; physiology ; Bone Development ; drug effects ; physiology ; Coated Materials, Biocompatible ; pharmacology ; Dogs ; Durapatite ; pharmacology ; Femur ; drug effects ; physiology ; Prostheses and Implants ; Titanium ; pharmacology ; Vacuum

Bones are stained into red color with feeding madder, but we do not know whether the fed madder can change the bone biomechanical properties and bone mineral contents in animals. In this research, we established a rat model with feeding madder. The bone biomechanical properties were detected by universal material mechanics, bone mineral contents were detected by inductively coupled plasma mass spectrometry and spectrometer, and red color material in bone was analyzed by high performance liquid chromatography. The results showed that bone biomechanical parameters in femur diaphysis in the 10% and 15% group rats were significantly higher than those in the control group after feeding madder for 6 months. The level of calcium, magnesium and zinc in femur diaphysis in 10% and 15% group rats were higher than those in the control group after feeding madder for 6 months. However, it was shown that the kidney congestion and hyperemia and the level of blood urea nitrogen and creatinine in the 15% group rats were significantly different compared to those in the control group rats after feeding madder for 6 months. The red colored material in bone is related to alizarin analyzed with high-performance liquid chromatography. The conclusion could be drawn that feeding 10% madder in diet was not toxic to the rats fed for 6 months, and it could improve bone biomechanical properties and increase bone mineral elements.
Animals ; Anthraquinones ; toxicity ; Biomechanical Phenomena ; Bone Density ; Bone and Bones ; drug effects ; physiology ; Calcium ; Femur ; Magnesium ; Rats ; Zinc

Autologous multipotent stem cells are most relevant cells for regenerative medicine and show prosperous future in the treatment of human diseases. Previous reports have indicated that multipotent stem cells (MSCs) can be obtained from bone marrow and adipose tissues. In this study, we proved that dermis may be another source of these cells. MSCs were isolated from the dermis of newborn rats one day old by adhesion competition and successive culture. These cells conserved the ability to differentiate to osteoblasts, chondrocytes and adipocytes by induction media containing dexamethasone. After long term of more than 6 months, till 25th generation, the cells still maintained the characteristics of stem cells: high activity of self-renewal and multipotency. Mixed collagen matrix from dermis could promote the growth of dermis-derived multipotent stem cells and collagen sponge stent could promote their three-dimensional growth in vitro.
Animals ; Biomechanical Phenomena ; Cell Culture Techniques ; methods ; Cells, Cultured ; Collagen ; pharmacology ; Dermis ; cytology ; Multipotent Stem Cells ; cytology ; drug effects ; physiology ; Rats ; Rats, Wistar

PURPOSE: Bone metastasis invariably increases morbidity and mortality. This study compares the effects of ibandronate and paclitaxel on bone structure and its mechanical properties and biochemical turnover in resorption markers using an immunocompetent Walker 256-Sprague-Dawley model, which was subjected to tumor-induced osteolysis. MATERIALS AND METHODS: Seventy rats were divided equally into 4 groups: 1) sham group (SHAM), 2) tumor group (CANC), 3) ibandronate treated group (IBAN), and 4) paclitaxel treated group (PAC). Morphological indices [bone volume fraction (BV/TV), trabecular number (Tb.N), trabecular thickness (Tb.Th), trabecular separation (Tb.Sp)] and mechanical properties (failure load, stiffness) were evaluated after thirty days of treatment period. Bone resorption rate was analysed using serum deoxypyridinoline (Dpd) concentrations. RESULTS: Morphological indices showed that ibandronate (anti-resorptive drug) had a better effect in treating tumor-induced architectural changes in bone than paclitaxel (chemotherapeutic drug). The deterioration in bone architecture was reflected in the biomechanical properties of bone as studied with decreased failure load (F(x)) and stiffness (S) of the bone on the 30th day postsurgery. Dpd concentrations were significantly lower in the IBAN group, indicating successful inhibition of bone resorption and destruction. CONCLUSION: Ibandronate was found to be as effective as higher doses of paclitaxel in maintaining stiffness of bone. Paclitaxel treatment did not appear to inhibit osteoclast resorption, which is contrary to earlier in-vitro literature. Emphasis should be placed on the use of immunocompetent models for examining drug efficacy since it adequately reflects bone metastasis in clinical scenarios.
Amino Acids ; Animals ; Biomechanical Phenomena/*drug effects/physiology ; Bone Density/drug effects/physiology ; Bone Neoplasms/*drug therapy ; Bone Resorption/*chemically induced ; Diphosphonates/*pharmacology ; Immunocompetence ; Male ; *Neoplasm Metastasis ; *Osteolysis ; Paclitaxel/*pharmacology ; Rats ; Rats, Sprague-Dawley

Biomechanical Phenomena ; methods ; trends ; Blood Circulation ; drug effects ; Blood Viscosity ; drug effects ; Drugs, Chinese Herbal ; pharmacology ; Endothelium, Vascular ; drug effects ; physiology ; Hemorheology ; methods ; trends ; Humans ; Medicine, Chinese Traditional ; methods ; trends ; Pharmacology ; methods ; trends ; Platelet Aggregation Inhibitors ; pharmacology

OBJECTIVETo observe the effect of Cuichan Zhusheng Decoction (CZD) on cervical maturation factors.

METHODSNinety women with full-term pregnancy and indication for labor inducing were assigned to three groups equally. The treated group was treated by water decoction of CZD, one dose (300 mL) daily, taken orally in the morning 30 min before breakfast, for successive 3 days, the administration would be discontinued if uterine contraction occurred for over 3 times/hour in the course. The control group was treated with pitocin by adding 1 U into 500 mL 5% glucose for intravenous dripping in 6 h, once every day for 3 successive days. The blank group was treated by placebo of CZD, administrated in same way as that in the treated group. The length and width of cervix and diameter of neck tube in all the women were measured on the very day of medication and 72 h later or parturient time by vaginal B-ultrasonography, and the cervical maturation degree was scored referring to the clinical Bishop scale. In the experimental study, the cervical tension of pregnant rats was measured with an in vitro cervical tension-meter, rats' cervical tissues were taken for pathologic examination to observe its morphological change.

RESULTSThe total effective rate for promoting cervical maturation was 96.67% in the treated group and 83.33% in the control group. It was significantly superior in the treated group to that in the control group and the blank group (P<0.05). Moreover, the cervical score in the treated group was higher in comparing with that in the blank group showing statistical significance (P<0.05). Animal experiments displayed that after medication, the cervical tissue of rat loosened with significantly lessened, swollen, convoluted and ruptured collagen fiber, showing sparse disorderly lined-up reticular status. Degradation of collagen fiber, vascular dilatation and congestion with massive amount of inflammatory cells infiltration, increased matrix components, and many leucocyte and fibroblast in the stroma could be seen.

CONCLUSIONCZD can change the morphorlogic structure of cervical tissue, decrease cervical tension, so as to promote the cervical maturation and induce labor.

Adult ; Animals ; Biomechanical Phenomena ; Cervical Ripening ; drug effects ; Cervix Uteri ; cytology ; drug effects ; metabolism ; physiology ; Collagen ; metabolism ; Drugs, Chinese Herbal ; pharmacology ; Female ; Humans ; Labor, Induced ; Pregnancy ; Rats ; Young Adult

OBJECTIVETo explore the diaphragmatic toxicity in doxorubicin (DOX)-treated rats and the related mechanisms, as well as the effects of Shengmai Injection (SMI, ) on the diaphragmatic dysfunction.

METHODSThirty Sprague-Dawley male rats were randomly divided into three groups: control, DOX-treated and DOX+SMI treated groups. DOX was given to rats in DOX and DOX+SMI groups in 6 equal doses [2.5 mg/kg, intraperitoneal injection (i.p.)], on alternate days, over a period of 2 weeks for a cumulative dose of 15 mg/kg. SMI was given to DOX+SMI rats in 12 doses (3 mL/kg, i.p.) for a period of 2 weeks before the administration of DOX and 2 weeks during the administration of DOX. The rats in the control group received equal volume of normal saline. Subsequently, the twitch and tetanic characteristics and force-frequency relationships, and the malondialdehyde (MDA) levels and the superoxide dismutase (SOD) activities, as well as the mRNA content and proteins of inducible nitric oxide synthase (iNOS) were determined.

RESULTSThe DOX-treated rats had decreased the peak twitch tension (Pt), maximal tetanic tension (P0) and force-frequency relationship as compared with the control rats (P<0.01), while the diaphragm contractility in rats treated with SMI were significantly higher than that in DOX-treated rats (P<0.01). The DOX-treated rats had increased MAD levels and decreased SOD activities (P<0.05), and SMI decreased the MDA levels and increased the SOD activities in DOX-treated rats (P<0.05). Ultrastructure of diaphragm in the DOX-treated rats revealed typical alterations including fracture of diaphragm fibers, and edema and degeneration of mitochondria; these changes were relieved by SMI treatment. The mRNA content and protein of iNOS in DOX-treated rats were remarkably higher than those in control rats (P<0.01), while SMI decreased the mRNA expression level of iNOS in DOX-treated rats (P<0.05).

CONCLUSIONSLipid peroxidation is responsible for DOX-induced diaphragm toxicity. SMI protects diaphragm muscles and their function from DOX impairment, and these beneficial effects may be somehow correlated with the decrease in expression of iNOS and lipid peroxidation.

Animals ; Biomechanical Phenomena ; drug effects ; Blotting, Western ; Diaphragm ; drug effects ; pathology ; physiology ; ultrastructure ; Doxorubicin ; adverse effects ; Drugs, Chinese Herbal ; pharmacology ; Gene Expression Regulation ; drug effects ; In Vitro Techniques ; Injections ; Male ; Malondialdehyde ; metabolism ; Muscle Contraction ; drug effects ; Nitric Oxide Synthase Type II ; genetics ; metabolism ; Oxidative Stress ; drug effects ; RNA, Messenger ; genetics ; metabolism ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo observe the mechanical properties of decellularized porcine aortic valve, and to explore the effects of precoating methods of biological scaffold on histocompatibility.

METHODSFresh porcine aortic valves were decellularized using trypsin, TritonX-100 and nuclease. Treated valves were evaluated by light microscopy, scanning electron microscopy (SEM) and mechanical test. Three groups of scaffold were precoated with phosphate buffered saline (PBS), poly-L-lysine (PLL) and fetal bovine serum (FBS) respectively. Myofibroblasts were seeded onto each scaffold. Light and electron microscopic observation was performed and MTT test was used to examine efficiency of cell attachment.

RESULTSHE stain and SEM showed that cells were almost absent in the treated leaflet. The wave-like collagen together with the whole three-dimensional structure was maintained. Compared with normal valves, the Max-load, Max-stress and elastic modulus decreased while the Max-strain increased (P<0.05). The result of MTT test showed more cells were attached on the valves treated with FBS compared to the other two groups. Histological investigations also confirm that the high degree of cell attachment on the valves precoated with FBS (F=129.26, P=0.000).

CONCLUSIONSEnzyme combined with detergent and nucleases can remove cells from porcine aortic valves. Meanwhile the mechanical properties of these valves may be altered. Precoating porcine aortic valve with FBS is an effective method to improve cell attachment, growth and increasing.

Animals ; Aortic Valve ; cytology ; drug effects ; physiology ; Biomechanical Phenomena ; Bioprosthesis ; Cell Adhesion ; Cell Proliferation ; Cells, Cultured ; Coated Materials, Biocompatible ; chemistry ; pharmacology ; Fibroblasts ; cytology ; Heart Valve Prosthesis ; Rats ; Swine ; Tissue Engineering ; methods ; Tissue Scaffolds ; chemistry

α-smooth muscle actin (α-SMA) and tenascin-C are stress-induced phenotypic features of myofibroblasts. The expression levels of these two proteins closely correlate with the extracellular mechanical microenvironment. We investigated how the expression of α-SMA and tenascin-C was altered in the periodontal ligament (PDL) under orthodontic loading to indirectly reveal the intrinsic mechanical microenvironment in the PDL. In this study, we demonstrated the synergistic effects of transforming growth factor-β1 (TGF-β1) and mechanical tensile or compressive stress on myofibroblast differentiation from human periodontal ligament cells (hPDLCs). The hPDLCs under higher tensile or compressive stress significantly increased their levels of α-SMA and tenascin-C compared with those under lower tensile or compressive stress. A similar trend was observed in the tension and compression areas of the PDL under continuous light or heavy orthodontic load in rats. During the time-course analysis of expression, we observed that an increase in α-SMA levels was matched by an increase in tenascin-C levels in the PDL under orthodontic load in vivo. The time-dependent variation of α-SMA and tenascin-C expression in the PDL may indicate the time-dependent variation of intrinsic stress under constant extrinsic loading.
Actins ; analysis ; drug effects ; Adult ; Animals ; Biomechanical Phenomena ; Cell Culture Techniques ; Cell Differentiation ; physiology ; Cells, Cultured ; Cellular Microenvironment ; physiology ; Humans ; Male ; Myofibroblasts ; physiology ; Orthodontic Wires ; Periodontal Ligament ; chemistry ; cytology ; Pressure ; Rats ; Rats, Sprague-Dawley ; Stress, Mechanical ; Tenascin ; analysis ; drug effects ; Time Factors ; Tooth Movement Techniques ; instrumentation ; Transforming Growth Factor beta1 ; pharmacology

Understanding the regulatory mechanism that controls the alteration of global gene expression patterns continues to be a challenging task in computational biology. We previously developed an ant algorithm, a biologically-inspired computational technique for microarray data, and predicted putative transcription-factor binding motifs (TFBMs) through mimicking interactive behaviors of natural ants. Here we extended the algorithm into a set of web-based software, Ant Modeler, and applied it to investigate the transcriptional mechanism underlying bone formation. Mechanical loading and administration of bone morphogenic proteins (BMPs) are two known treatments to strengthen bone. We addressed a question: Is there any TFBM that stimulates both "anabolic responses of mechanical loading" and "BMP-mediated osteogenic signaling"? Although there is no significant overlap among genes in the two responses, a comparative model-based analysis suggests that the two independent osteogenic processes employ common TFBMs, such as a stress responsive element and a motif for peroxisome proliferator-activated receptor (PPAR). The post-modeling in vitro analysis using mouse osteoblast cells supported involvements of the predicted TFBMs such as PPAR, Ikaros 3, and LMO2 in response to mechanical loading. Taken together, the results would be useful to derive a set of testable hypotheses and examine the role of specific regulators in complex transcriptional control of bone formation.
Algorithms ; Animals ; Base Sequence ; Binding Sites ; genetics ; Biomechanical Phenomena ; Bone Morphogenetic Proteins ; pharmacology ; Consensus Sequence ; DNA ; genetics ; metabolism ; Databases, Genetic ; Gene Expression Profiling ; statistics & numerical data ; Genomics ; statistics & numerical data ; Mice ; Oligonucleotide Array Sequence Analysis ; statistics & numerical data ; Osteoblasts ; drug effects ; metabolism ; Osteogenesis ; drug effects ; genetics ; physiology ; Transcription Factors ; metabolism